Video timing test equipment and methods of using the same for measuring light integration time of a camera

ABSTRACT

A video timing test equipment for measuring light integration time of a camera. The video timing test equipment may comprise: a control unit and shutter timing test unit. The control unit may generate input timing signals adjustable by a user. The shutter timing test unit may comprise light emitting diodes (LEDs), infrared light emitting diodes (IR LEDs), and an output controller. The output controller may regulate the illumination of the LEDs and IR LEDs based on the input timing signals. The shutter timing test unit may also comprise a UTC time display, edge time display, and pulse width display. The UTC time display may depict a UTC time as to when light integration begins or ends. The edge time display may depict an offset time associated with the start or end of light integration. The pulse width display may depict the duration of light integration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional patent application of the commonlyowned, U.S. non-provisional patent application Ser. No. 15/596,142,titled “Video Timing Test Equipment and Methods of Using the Same ForMeasuring Light Integration Time of a Camera,” filed on May 16, 2017 byco-inventors James Higdon and Jason Witzel, the contents of which ishereby expressly incorporated herein by reference in its entirety and towhich priority is claimed.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The invention disclosed herein may be manufactured and used by or forthe government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

FIELD

The present disclosure relates generally to test equipment for camerashutter systems and, more particularly, to calibration mechanisms formeasuring light integration time of a camera under test, includingvisible cameras and infrared cameras.

BACKGROUND

In order to support testing and training activities, many open airranges utilize multiple cameras to capture images in both visible andnon-visible spectra. These cameras are generally used to record a testevent and are generally synchronized to a precision time source (e.g.,coordinated time source (UTC)) to help create coordinated imagery of thetest event. The resulting imagery capturing the test event is thenpreferably fed into image processing software and fused to generateposition versus time data or time-space-position information (TSPI)data.

The resulting TSPI data, however, may be susceptible to error and isgenerally only as precise as the least precise data source used togenerate that data. Thus, any improvement to the accuracy of the timingof the camera shutter speeds will likely result in an improvement in thegenerated TSPI data. The frame rate for some of these cameras can bealtered, thereby modifying how often an image frame is recorded for eachspecific test. But, depending on the manufacturer of each camera device,the timing of the camera shutter may vary, even when using the sameinput synchronization signal. More importantly, in some cases, theshutter timing might not even conform to the manufacturer-providedspecifications. As a result, given the possible shutter timinginconsistencies of the cameras, it might become more difficult orimpossible to determine the timing of critical events with a necessarydegree of precision.

Therefore, based on the foregoing, a need exists that overcomes thesedeficiencies. The present disclosure solves the inconsistent shuttertiming deficiencies and generally represents a new and useful innovationin the realm of calibration mechanisms for measuring with precision thetiming of light integration for cameras.

SUMMARY OF ILLUSTRATIVE EMBODIMENTS

To minimize the limitations in the related art and other limitationsthat will become apparent upon reading and understanding the presentspecification, the following discloses a new and useful video timingtest equipment and methods of using the same for measuring lightintegration time of a camera.

One embodiment may be a video timing test equipment for measuring lightintegration time of a camera under test, comprising: a control unitcapable of generating a plurality of input timing signals adjustable bya user; and a shutter timing test unit operatively coupled to thecontrol unit, the shutter timing test unit comprising: a plurality oftiming light emitting diodes (LEDs), including: at least one left timingLED, a center timing LED, and at least one right timing LED; and anoutput controller capable of regulating an illumination of the pluralityof timing LEDs by generating a plurality of timing LED output signals,each having an offset time occurring sequentially and corresponding toan associated one of the plurality of timing LEDs; wherein the pluralityof timing LED output signals may be adjusted by the user based on theplurality of input timing signals and may include a center timing LEDoutput signal associated with the illumination of the center timing LED;and wherein the output controller may be configured to: (i) illuminatethe center timing LED based on the offset time of the center timing LEDoutput signal; (ii) illuminate the at least one left timing LED beforethe illumination of the center timing LED; and (iii) illuminate the atleast one right timing LED after the illumination of the center timingLED. The shutter timing test unit may further comprise: a coordinateduniversal time (UTC) time display in communication with the outputcontroller; a UTC timing module capable of generating a current UTC timesignal; and a timing logic capable of generating a center timing LED UTCtime matching signal based on the current UTC time signal and theplurality of input timing signals; wherein the output controller may becapable of displaying on the UTC time display a UTC time based on thecenter timing LED UTC time matching signal, the UTC time correspondingto a UTC start time or a UTC end time of the light integration. Theshutter timing test unit may further comprise: a plurality of binarycoded decimal (BCD) LEDs in communication with the output controller;and wherein the output controller may be capable of displaying the UTCtime in BCD format with the plurality of BCD LEDs. The shutter timingtest unit may further comprise: a plurality of BCD infrared lightemitting diodes (IR LEDs) in communication with the output controller;wherein the output controller may be capable of displaying the UTC timein BCD format with the plurality of BCD IR LEDs. The shutter timing testunit may further comprise: a user input display logic; and an edge timedisplay in communication with the user input display logic; wherein theuser input display logic may be capable of displaying the offset time ofthe center timing LED on the edge time display based on the plurality ofinput timing signals. The shutter timing test unit may further comprise:a pulse width display in communication with the user input displaylogic; wherein the user input display logic may be capable of displayinga pulse width time on the pulse width display based on the plurality ofinput timing signals. The shutter timing test unit may further comprise:a plurality of timing IR LEDs, including at least one left timing IRLED, a center timing IR LED, and at least one right timing IR LED;wherein the output controller may be capable of regulating anillumination of the plurality of timing IR LEDs based on the pluralityof timing LED output signals, such that the output controller may beconfigured to: (i) illuminate the center timing IR LED based on theoffset time of the center timing LED output signal; (ii) illuminate theat least one left timing IR LED before the illumination of the centertiming IR LED; and (iii) illuminate the at least one right timing IR LEDafter the illumination of the center timing IR LED. The control unit maycomprise a toggle switch movable between a start position and an endposition, the start position being associated with a leading edge of thecenter timing LED output signal and the end position being associatedwith a trailing edge of the center timing LED output signal, such thatthe start position corresponds to a start of light integration and theend position corresponds to an end of the light integration.

Another embodiment may be a video timing test equipment for measuringlight integration time of a camera under test, comprising: a controlunit capable of generating a plurality of input timing signalsadjustable by a user; and a shutter timing test unit operatively coupledto the control unit, the shutter timing test unit comprising: aplurality of timing LEDs, including: at least one left timing LED, acenter timing LED, and at least one right timing LED; a timing logiccapable of generating a first timing LED start time signal and a pulsewidth signal, based on the plurality of input timing signals, whereinthe first timing LED start time signal may correspond to a start time asto when a first of the plurality of timing LEDs begins to illuminate andwherein the pulse width signal may correspond to a time period forilluminating each of the plurality of timing LEDs; an output controllercapable of regulating an illumination of the plurality of timing LEDs bygenerating a plurality of timing LED output signals, each having anoffset time occurring sequentially and corresponding to an associatedone of the plurality of timing LEDs, the plurality of timing LED outputsignals being adjusted based on: (1) the first timing LED start timesignal and (2) the pulse width signal and including a center timing LEDoutput signal associated with the illumination of the center timing LED;wherein the output controller may be configured to: (i) illuminate thecenter timing LED based on the offset time of the center timing LEDoutput signal; (ii) illuminate the at least one left timing LED beforethe illumination of the center timing LED; and (iii) illuminate the atleast one right timing LED after the illumination of the center timingLED. The shutter timing test unit may further comprise: a UTC timingmodule capable of generating a current UTC time signal; and a UTC timedisplay in communication with the output controller; wherein the timinglogic may be capable of generating a center timing LED UTC time matchingsignal based on the current UTC time signal and the plurality of inputtiming signals; and wherein the output controller may be capable ofdisplaying on the UTC time display a UTC time based on the center timingLED UTC time matching signal, the UTC time corresponding to a UTC starttime or a UTC end time of the light integration. The shutter timing unitmay further comprise: a plurality of timing IR LEDs, including at leastone left timing IR LED, a center timing IR LED, and at least one righttiming IR LED; wherein the output controller may be capable ofregulating an illumination of the plurality of timing IR LEDs based onthe plurality of timing LED output signals, such that the outputcontroller may be configured to: (i) illuminate the center timing IR LEDbased on the offset time of the center timing LED output signal; (ii)illuminate the at least one left timing IR LED before the illuminationof the center timing IR LED; and (iii) illuminate the at least one righttiming IR LED after the illumination of the center timing IR LED. Theshutter timing test unit may further comprise: a plurality of BCD LEDsin communication with the output controller; wherein the outputcontroller may be capable of displaying the UTC time in BCD format withthe plurality of BCD LEDs. The shutter timing test unit may furthercomprise: a plurality of BCD IR LEDs in communication with the outputcontroller; wherein the output controller may be capable of displayingthe UTC time in BCD format using the plurality of BCD IR LEDs. Theshutter timing test unit may further comprise: a user input displaylogic; and an edge time display in communication with the user inputdisplay logic; wherein the user input display logic may be capable ofdisplaying the offset time of the center timing LED on the edge timedisplay based on the plurality of input timing signals. The shuttertiming test unit may further comprise: a pulse width display incommunication with the user input display logic; wherein the user inputdisplay logic may be capable of displaying a pulse width time on thepulse width display based on the plurality of input timing signals. Thecontrol unit may comprise a toggle switch movable between a startposition and an end position, the start position being associated with aleading edge of the center timing LED output signal and the end positionbeing associated with a trailing edge of the center timing LED outputsignal, such that the start position corresponds to a start of lightintegration and the end position corresponds to an end of the lightintegration.

Another embodiment may be a method for measuring light integration timeof a camera under test with a video timing test equipment, comprising:providing a video timing test equipment having a control unit and ashutter timing test unit; wherein the control unit may be capable ofgenerating a plurality of input timing signals adjustable by a user andmay comprise: (1) a toggle switch and (2) at least one rotary controlknob; wherein the toggle switch may be selectable between a start oflight integration and an end of light integration and wherein the atleast one rotary control knob may be used to adjust an offset time ofthe start and the end of light integration; wherein the shutter timingtest unit may be operatively coupled to the control unit and maycomprise: a plurality of timing LEDs, including: at least one lefttiming LED, a center timing LED, and at least one right timing LED; andan output controller capable of regulating an illumination of theplurality of timing LEDs by generating a plurality of timing LED outputsignals, each having an offset time increasing successively andcorresponding to an associated one of the plurality of timing LEDs, theplurality of timing LED output signals being adjusted based on theplurality of input timing signals and includes a center timing LEDoutput signal associated with the illumination of the center timing LED;wherein the output controller may be configured to: (i) illuminate thecenter timing LED based on the offset time of the center timing LEDoutput signal; (ii) illuminate the at least one left timing LED beforethe illumination of the center timing LED; and (iii) illuminate the atleast one right timing LED after the illumination of the center timingLED; positioning the shutter timing test unit in view of a camera undertest, such that, a monitor in video communication with the camera undertest may display a video image of the timing LEDs of the shutter timingtest unit; adjusting the toggle switch of the control unit to select thestart of light integration; and, while viewing the timing LEDs on themonitor, adjusting the at least one control knob of the control unituntil the at least one left timing LED stops illuminating and the centertiming LED illuminates in order to measure the start of the lightintegration. The method may further comprise the steps: adjusting thetoggle switch of the control unit to select the end of the lightintegration; and, while viewing the timing LEDs on the monitor,adjusting the at least one control knob of the control unit until the atleast the center timing LED illuminates and the at least one righttiming LED stops illuminating in order to determine the end of lightintegration. The shutter timing test unit may further comprise a UTCtime display; wherein the UTC time display may depict a UTC start timewhen selecting the start of the light integration with the control unit;and wherein the method may further comprise the steps: adjusting thetoggle switch of the control unit to select the start of lightintegration; and verifying that a UTC time overlay displayed on themonitor and generated by the camera under test is substantiallyidentical to the UTC start time depicted on the UTC time display of theshutter timing test unit. The UTC time display may depict a UTC end timewhen selecting the end of light integration with the control unit; andwherein the method may further comprise the steps: adjusting the toggleswitch of the control unit to select the end of light integration; andverifying that a UTC time overlay displayed on the monitor and generatedby the camera under test is substantially identical to the UTC end timedepicted on the UTC time display of the shutter timing test unit.

In one embodiment, the current time signal may be modulated with timedata according to Inter Range Instrumentation Group (IRIG) code. Thecontrol unit may comprise a toggle switch movable between a startposition and an end position, the start position corresponding to astart of light integration and the end position corresponding to an endof the light integration.

It is an object to provide video timing test equipment and methods forusing the same for measuring and verifying the exact shutter time andspeed of each camera (i.e., visible and infrared cameras) to the nearestmicrosecond for frame rates up to 1,600 frames per second.

It is an object to overcome the limitations of the prior art.

These, as well as other components, steps, features, objects, benefits,and advantages, will now become clear from a review of the followingdetailed description of illustrative embodiments, the accompanyingdrawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are illustrative embodiments. They do not illustrate allembodiments. They do not set forth all embodiments. Other embodimentsmay be used in addition or instead. Details, which may be apparent orunnecessary, may be omitted to save space or for more effectiveillustration. Some embodiments may be practiced with additionalcomponents or steps and/or without all of the components or steps, whichare illustrated. When the same numeral appears in different drawings, itis intended to refer to the same or like components or steps.

FIG. 1 is an illustration of a test setup for one embodiment of thevideo timing test equipment for measuring light integration time of acamera under test.

FIG. 2 is an illustration of one embodiment of a shutter timing testunit as depicted on a video monitor and shows the shutter timing testunit at the beginning of light integration.

FIG. 3 is an illustration of one embodiment of a shutter timing testunit as depicted on a video monitor and shows the shutter timing testunit at the end of light integration.

FIG. 4 is an illustration of one embodiment of a control unit and showshow the settings of the control unit would be adjusted in order tomeasure the start of light integration.

FIG. 5 is an illustration of one embodiment of a control unit and showshow the settings of the control unit would be adjusted in order tomeasure the end of light integration.

FIG. 6 is a block diagram of the video timing test equipment accordingto various embodiments of the present disclosure.

FIGS. 7A and 7B are illustrations of some embodiments of the timingLEDs, timing IR LEDs, and timing LED output signals and show the timingrelationship of these timing LEDs, timing IR LEDs, and timing LED outputsignals.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of various aspects ofone or more embodiments of the video timing test equipment. However,these embodiments may be practiced without some or all of these specificdetails. In other instances, well-known methods, procedures, and/orcomponents have not been described in detail so as not to unnecessarilyobscure aspects of these embodiments.

While multiple embodiments of the video timing test equipment aredisclosed, still other embodiments will become apparent to those skilledin the art from the following detailed description. As will be realized,the following embodiments of the video timing test equipment may becapable of modifications in various obvious aspects, all withoutdeparting from the spirit and scope of protection. Accordingly, thegraphs, figures, and the detailed descriptions thereof, are to beregarded as illustrative in nature and not restrictive. Also, thereference or non-reference to a particular embodiment shall not beinterpreted to limit the scope of the disclosure.

Before the embodiments are disclosed and described, it is to beunderstood that this these embodiments are not limited to the particularstructures, process steps, or materials disclosed herein, but isextended to equivalents thereof as would be recognized by thoseordinarily skilled in the relevant arts. It should also be understoodthat terminology employed herein is used for the purpose of describingparticular embodiments only and is not intended to be limiting.

It should also be understood that some of the functional units describedin this specification might have been labeled as modules, in order tomore particularly emphasize their implementation independence. Forexample, a module may be implemented as a hardware circuit comprisingcustom VLSI circuits or gate arrays, off-the-shelf semiconductors suchas logic chips, transistors, or other discrete components. A module mayalso be implemented in programmable hardware devices such as fieldprogrammable gate arrays, programmable array logic, programmable logicdevices or the like.

Modules may also be implemented in software for execution by varioustypes of processors. An identified module of executable code may, forinstance, comprise one or more physical or logical blocks of computerinstructions, which may, for instance, be organized as an object,procedure, or function. Nevertheless, the executables of an identifiedmodule need not be physically located together, but may comprisedisparate instructions stored in different locations which, when joinedlogically together, comprise the module and achieve the stated purposefor the module.

Indeed, a module of executable code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be identified and illustrated hereinwithin modules, and may be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data may becollected as a single data set, or may be distributed over differentlocations including over different storage devices, and may exist, atleast partially, merely as electronic signals on a system or network.The modules may be passive or active, including agents operable toperform desired functions.

Reference throughout this specification to “one embodiment”, “anembodiment”, or “another embodiment” may mean that a particular feature,structure, or characteristic described in connection with the embodimentmay be included in at least one embodiment of the present disclosure.Thus, appearances of the phrases “in one embodiment” or “in anembodiment” in various places throughout this specification may notnecessarily refer to the same embodiment.

Furthermore, the described features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments. In thefollowing description, numerous specific details are provided, such asexamples of materials, fasteners, sizes, lengths, widths, shapes, etc .. . , to provide a thorough understanding of the embodiments. Oneskilled in the relevant art will recognize, however, that the scope ofprotection can be practiced without one or more of the specific details,or with other methods, components, materials, etc . . . . In otherinstances, well-known structures, materials, or operations are generallynot shown or described in detail to avoid obscuring aspects of thedisclosure.

Definitions

In the following description, certain terminology is used to describecertain features of one or more embodiments. For example, as usedherein, the terms “camera,” “visible camera,” and “infrared camera”generally refer to an optical device or component capable of acquiring,capturing, and/or recording visual images of an object of interest inthe form of image and/or video signals. In other embodiments, a cameramay also be used to capture and/or record visual images in the form ofphotographs and film.

As used herein, the terms “application”, “software”, or “softwareapplication” generally refer to any set of machine-readable instructionson a client machine, web interface, and/or computer system, that directsa computer's processor to perform specific steps, processes, oroperations disclosed herein.

As used herein, the term “display” refers to display elements includingbut not limited to seven-segment displays, light emitting diodes (LEDs),or the like.

As used herein, the term “pulse width” refers to the amount of time,within a period of a signal (e.g., a digital pulse width modulationvoltage signal), that the value of the signal is above or below areference value (e.g., electrical ground).

As used herein, the singular forms “a” and “the” may include pluralreferents, unless the context clearly dictates otherwise. Thus, forexample, reference to a “display”, “UTC time display”, “edge timedisplay”, or “pulse width time display” can include reference to one ormore of such displays.

The present disclosure is directed to video timing test equipment foraccurately measuring the start time and end time of light integrationfor cameras, including visible cameras and infrared cameras. In general,the video timing test equipment may utilize a camera or video recorder,preferably with single frame step, to measure the accuracy of videooverlay and metadata time stamp. In one embodiment, the video timingtest equipment may utilize a global positioning system (GPS) coordinateuniversal time (UTC) time message signal along with a one pulse persecond (1PPS) output signal to generate a timing accuracy ofapproximately one microsecond. Preferably, the timing accuracy isexpressed through the use of light emitting diodes (LEDs) and infrared(IR) LEDs, which may be synchronized to a video frame rate signal. Thus,various embodiments of the video timing test equipment may utilize highspeed LEDs (i.e., switching within 0-100 nanoseconds).

In various embodiments, the video timing test equipment may comprisethree components: (1) shutter timing test unit, (2) a control unit, and(3) a GPS receiver for generating the UTC time message signal. In someembodiments, the GPS receiver may be internal to or integrated with theshutter timing test unit or control unit, but may be a separateindependent device. Similarly, in other embodiments, the shutter timingtest unit and control unit may be integrated as a single device or maybe separate independent devices.

The shutter timing test unit generally serves as a calibration timingdisplay unit and may comprise three major components: (i) timing LEDsfor measuring the integration time of a light sensor of a camera, (ii)digital display (e.g., seven segment displays) or LED display fordisplaying UTC time, and (iii) various indicators and displays forshowing edge time, pulse width, frame rate, and offset time.

The control unit may be used generate input timing signals, and theseinput timing signals may be adjustable by a user. Importantly, the inputtiming signals may be used to synchronize the timing of the LEDs withthe start and end times of light integration.

When measuring the start of light integration, the user may adjust theoffset time or edge time in one microsecond steps until (1) the centertiming LED illuminates and (2) timing LED just to the left of the centertiming LED extinguishes. Here, the UTC time portion of the display maybe locked to the exact time when the center timing LED firstilluminates, so that the UTC time is stable on the recording for theentire video frame for any integration time selected for the camera.

On the other hand, when measuring the end of light integration, the usermay adjust the offset time or edge time in one microsecond steps until(1) the center timing LED illuminates and (2) the timing LED just to theright of the center timing LED extinguishes. Here, the UTC time portionof the display may be locked to the exact time when the center timingLED first turns off, so that the UTC time is stable on the recording forthe entire video frame for any integration time selected for the camera.

FIG. 1 is an illustration of a test setup for one embodiment of thevideo timing test equipment for measuring light integration time of acamera under test. As shown in FIG. 1, one embodiment of a test setup 10may comprise: a video timing test equipment 100, visible camera 105,infrared camera 110, video synchronizer and time overlay generator 115,video recorder 120, and monitor 125. The video timing test equipment 100may comprise: a GPS receiver 200, shutter timing test unit 300, and acontrol unit 400.

FIG. 1 shows that the visible camera 105 may be in video communicationwith the video synchronizer and time overlay generator 115 in order totransmit a visible video signal 106 to the video synchronizer and timeoverlay generator 115. This may allow the visible camera 105 to transmitvisible light images to the video synchronizer and time overlaygenerator 115. Similarly, FIG. 1 shows that the infrared camera 110 mayalso be in video communication with the video synchronizer and timeoverlay generator 115 in order to transmit an infrared video signal 111to the video synchronizer and time overlay generator 115. This may alsoallow the infrared camera 110 to also transmit infrared light images tothe video synchronizer and time overlay generator 115. Given that bothvideo signals may be transmitted to the video synchronizer and timeoverlay generator 115, the video synchronizer and time overlay generator115 may synchronize both of these video signals to create a synchronizedvideo signal 117. The video synchronizer and time overlay generator 115may also transmit a camera vertical synchronization signal 116 to thevisible camera 105 and/or infrared camera 110 in order to helpsynchronize the infrared video signal 111 and visible video signal 106.

FIG. 1 also shows that the video synchronizer and time overlay generator115 may output the synchronized video signal 117 to a monitor 125 and/orvideo recorder 120. This may allow the user to view the video signalscaptured by the visible camera 105 and infrared camera 110. The user mayalso record the synchronized video signal 117 with the video recorder120 for record keeping. Importantly, the use of a video recorder 120with a single frame step may help measure the accuracy of the videooverlay and meta data time stamp (i.e., UTC time). This may beaccomplished by having the user compare the meta data time stampgenerated by the synchronizer and time overlay generator 115 with thecurrent UTC time obtained from the GPS receiver. Although FIG. 1 showsthat a video recorder 120 is used for the test setup 10, the user maycreate a test setup without a video recorder.

FIG. 1 also shows that the video timing test equipment 100 may comprisethree separate units: a GPS receiver 200, a shutter timing test unit300, and a control unit 400. The GPS receiver 200 may be a typicalreceiver configured to acquire GPS signals (i.e., a UTC time message 201and a one pulse per second (1PPS) GPS signal 202 (e.g., L1 signal)) andmay be configured to output those signals to the shutter timing testunit 300. The GPS signals may also be used to determine UTC timeinformation.

The control unit 400 may be a control interface that allows a user toselect various timing inputs for the video timing test equipment 100. Inparticular, when using the control unit 400, the user may select andadjust the timing and frame rate (i.e., frequency) of the illuminationof the shutter timing test unit's 300 light emitting diodes (LEDs) andinfrared light emitting diodes (IR LEDs). For example, in oneembodiment, the user, when using the control unit 400, may select theframe rate, start/end of light integration time, timing of theillumination of the LEDs, and the offset timing of the illumination ofthe centermost LED from the vertical video frame. In variousembodiments, the control unit 400 may also allow the user to adjust theresolution timing such as 100, 10, and 1 microsecond units. As a result,the control unit 400 may generate and transmit multiple input timingsignals to the shutter timing test unit 300.

FIG. 1 also shows that the video timing test equipment 100 may comprisea shutter timing test unit 300. The shutter timing test unit 300 may betest equipment, comprising LEDs and IR LEDs and may be used to regulatethe illumination of those LEDs and IR LEDs based on the user-inputtedselected settings. In this manner, the shutter timing test unit 300 mayvisually display various timing data configured by the user. Such timingdata may include, without limitation, edge time, pulse width time, andUTC time. In various embodiments, the UTC time may be synchronized withthe illumination of one or more LEDs, such as timing LEDs, timing IRLEDs, binary coded decimal (BCD) LEDs, and BCD IR LEDs. In a preferredembodiment, the UTC time may be synchronized with the center timing LEDand center timing IR LED. Preferably, the shutter timing test unit 300utilizes high speed LEDs such as LEDs with less than 100 nanosecondswitching.

Importantly, FIG. 1 also shows that the video timing test equipment 100may be positioned within view of the visible camera 105 and/or infraredcamera 110. As a result, the user may view the video timing testequipment 100 with the monitor 125 in order to observe the illuminationactivity of the LED and display components of the shutter timing testunit 300. In particular, the user may be able to view and observe theaction of various components of the video timing test equipment 100 suchas LEDs (i.e., timing LEDs 320, BCD LEDs 325, timing IR LEDs 330, BCD IRLEDs 335) (all shown in FIGS. 2 and 3) and displays (i.e., UTC timedisplay 305, edge time display 310, pulse width display 315) (all shownin FIGS. 2 and 3). Thus, by adjusting the timing inputs generated by thecontrol unit 400 and observing the LED and display components of theshutter timing test unit 300, the user may be able to synchronize thetiming of the video frame rate signal with the illumination of the LEDsand IR LEDs in order to measure light integration time. Moreover, asrecited above, the user may be able to verify the UTC time generated bythe visible camera 105 and infrared camera 110 by comparing the UTC timeoverlay displayed on the monitor 125 (created by the video synchronizerand time overlay generator 115) with the actual UTC time obtained fromthe GPS receiver 200. Additional details as to how to measure lightintegration and verify UTC time are discussed below.

Although FIG. 1 shows that the video timing test equipment 100 maycomprise three separate units (i.e., the GPS receiver 200, shuttertiming test unit 300, and a control unit 400), various embodiments ofthe video timing test equipment may comprise one, two, or threestandalone devices. For example, in one embodiment of the video timingtest equipment, the GPS receiver 200, shutter timing test source 300,and a control unit 400 may be integrated as a single unit or device. Onthe other hand, another embodiment of the video timing test equipmentmay comprise two standalone devices. For instance, in one embodiment,the video timing test equipment may be two separate devices: (1) controlunit and (2) the GPS receiver and shutter timing test unit as a singlestandalone device. Alternatively, another embodiment of the video timingtest equipment may be two different devices: (1) the GPS receiver and(2) the shutter timing test unit and control unit as a single standalonedevice.

FIG. 2 is an illustration of one embodiment of a shutter timing testunit as depicted on a video monitor and shows the shutter timing testunit at the beginning of light integration. As shown in FIG. 2, oneembodiment of the shutter timing test unit 300 may comprise: a UTC timedisplay 305, an edge time display 310, a pulse width display 315, timingLEDs 320, BCD LEDs 325, timing IR LEDs 330, BCD IR LEDs 335, a startedge select LED indicator 340, a start edge select IR LED indicator 345,an end edge select LED indicator 350, an end edge select IR LEDindicator 355, a GPS/IRIG lock indicator 360, a timer lock indicator365, and a power indicator 370. Additionally, the timing LEDs 320 mayinclude: left timing LEDs 321, a center timing LED 322, and right timingLEDs 323. The timing IR LEDs 330 may include: left timing IR LEDs 331, acenter timing IR LED 332, and right timing IR LEDs 333.

The UTC time display 305 may be one or more alphanumeric display devices(e.g., seven segment displays) configured to depict UTC time from0.000,000 seconds to 9.999,999 seconds and may include various timeunits, such as seconds, milliseconds, and/or microseconds. Importantly,the UTC time display 305 preferably displays a UTC time that issynchronized or locked with the timing of the illumination of the centertiming LED 322 and center timing IR LED 332. Thus, when the centertiming LED 322 and center timing IR LED 332 begin illuminating, the UTCtime depicted on the UTC time display 305 should match with the UTC timeoverlay 335 displayed in the monitor 125. This may depend on whether anLED and IR LED adjacent to the center timing LED 322 and center timingIR LED 332 also illuminate (i.e., left timing LED 321 a, left timing IRLED 331 a, right timing LED 323 a, right timing IR LED 333 a). In thismanner, the user may verify that the data of the UTC time overlay 335generated from the video synchronizer and time overlay generator 115matches with the current UTC time and actual time the camera isgathering light, which is the beginning of light integration.

The edge time display 310 may be one or more alphanumeric displaydevices (e.g., seven segment displays) configured to depict an offsettime associated with a leading edge or a trailing edge of one or moreinput timing signals. This offset time may also be synchronized with theillumination of the center timing LED 322 and center timing IR LED 332from the vertical frame and may be depicted in microseconds.

The pulse width display 315 may be one or more alphanumeric displaydevices (e.g., seven segment displays) configured to characterize thelength of the pulse width of one or more input timing signals. The pulsewidth may refer to the period of time or duration at which the signal isabove or below a reference value such as electrical ground and thus maycontrol the length or duration of the illumination of the timing LEDs320 and timing IR LEDs 330. FIG. 2 shows that, in one embodiment, thepulse width display 315 may express the pulse width in microseconds.

The timing LEDs 320 may be a group of LEDs capable of emitting visiblelight for purposes of measuring the start or end of light integration ofa camera's light sensor. The timing LEDs 320 may include: one or moreleft timing LEDs 321, a center timing LED 322, and one or more righttiming LEDs 323 and may emit visible light in a consecutive andsuccessive pattern based on the positions of each adjacent timing LED320. In particular, the shutter timing test unit 300 may generatemultiple timing LED output signals, and each timing LED output signalmay correspond to a particular timing LED 320. Importantly, as shown inFIG. 7, the timing LED output signals may each comprise a pulse widthwaveform, and each pulse width waveform may occur sequentially andconsecutively, such that one or more timing LEDs 320 emit visible lightsuccessively and adjacently. For example, in one embodiment, the shuttertiming test unit 300 may emit five LED output signals, each of which maycomprise a pulse width waveform in successive timing offsets. Thus, thefive LED output signals may then be used to successively illuminate fivetiming LEDs 320.

Similarly, the timing IR LEDs 330 may also be a group of IR LEDs capableof emitting infrared light for purposes of measuring the start or end oflight integration of an infrared camera's light sensor. Thus, unlike thetiming LEDs 320, which are adapted to emit visible light, the timing IRLEDs 330 may be adapted to emit infrared light visible to the infraredcamera 110. The timing IR LEDs 330 may include: one or more left timingIR LEDs 331, a center timing IR LED 332, and one or more timing IR LEDs333 and may emit infrared light in a consecutive and successive patternbased on the positions of each adjacent timing IR LED 330. Inparticular, the shutter timing test unit 300 may generate multipletiming LED output signals, and each timing LED output signals maycorrespond with a particular timing IR LED 330. Importantly, as shown inFIG. 7, the timing LED output signals may each comprise a pulse widthwaveform occurring sequentially and consecutively, such that eachadjacent timing IR LED 330 emits infrared light successively andadjacently. For example, in one embodiment, the shutter timing test unit300 may emit five timing LED output signals, each of which may comprisea pulse width waveform in successive timing offsets. Thus, the five LEDoutput signals may then be used to successively illuminate five timingIR LEDs 330.

It is important to note that, in preferred embodiments, the sequence ofinfrared light emissions by the timing IR LEDs 330 may be identical tothe sequence of visible light emissions by the timing LEDs 320. Thatway, the UTC time depicted on the UTC time display 305, reference edgetime value depicted on the edge time display 310, and pulse width valuedepicted on the pulse width display 315 may synchronize with the lightemissions of the center timing LED 322 and center timing IR LED 332.

FIG. 2 also shows that the shutter timing test unit 300 may comprise BCDLEDs 325 and BCD IR LEDs 335. The BCD LEDs 325 and BCD IR LEDs 335 maybe a group of LEDs and IR LEDs capable of depicting UTC time in BCDformat. In particular, the BCD LEDs 325 and BCD IR LEDs 335 may depictin BCD format the UTC time displayed on the UTC time display 305. Forexample, as shown in FIG. 2, BCD LEDs 325 and BCD IR LEDs 335 may showthe UTC time as 1.234,567 seconds.

The UTC time display 305, edge time display 310, and pulse width display315 are generally human readable devices that must be activated wellbefore the illuminations of the center timing LED 322 and center timingIR LED 332. Therefore, the time associated with the illuminations of thecenter timing LED 322 and center timing IR LED 332 may be pre-computedand latched into a display driver when the left timing LEDs 321 and lefttiming IR LEDs 331 are first lit. In this manner, the BCD LEDs 325 andBCD IR LEDs 335 may then be illuminated and gated onto a bus at the timewhen the center timing LED 322 and center timing IR LED 332 are lit.

Furthermore, FIG. 2 shows that the shutter timing test unit 300 maycomprise a GPS/IRIG lock indicator 360, a timer lock indicator 365, anda power indicator 370. The GPS/IRIG lock indicator 360 may illuminatewhen an IRIG time code signal is applied. The timer lock indicator 365may illuminate when the shutter timing test unit 300 is locked to a UTCcarrier signal. The power indicator 370 may illuminate to indicate whenthe shutter timing test unit 300 is on.

Finally, FIG. 2 shows the shutter timing test unit 300 at the beginningor start of light integration. In order to accurately measure thebeginning of light integration, the user may select the left edge orleading edge of the edge select switch 410 (shown in FIG. 4), which maybe a toggle switch on the control unit 400. As a result, the UTC timedepicted on the UTC time display 305 may be synced to the moment whenthe center timing LED 322 and center timing IR LED 332 first illuminate.The user may also adjust the other settings on the control unit 400 asshown in FIG. 4. In particular, the user may adjust the offset time insingle microsecond steps until: (1) the center timing LED 322 and centertiming IR LED 332 illuminate; (2) the left timing LED 321 a adjacent tothe center timing LED 322 does not illuminate, and (3) the left timingIR LED 331 a adjacent to the center timing IR LED 332 does notilluminate. At this time, both the start edge select LED indicator 340and a start edge select IR LED indicator 345 may illuminate, therebyconfirming that the leading edge of a pulse signal is selected formeasuring the start of light integration. The UTC time shown in the UTCtime display 305 may also be synchronized to the leading edge of thatpulse signal at this time—that is, when: (1) the center timing LED 322and center timing IR LED 332 illuminate; (2) the left timing LED 321 aadjacent to the center timing LED 322 does not illuminate, and (3) lefttiming IR LED 331 a adjacent to the center timing IR LED 332 does notilluminate. Thus, as the left timing LED 321 a and the left timing IRLED 331 a illuminate, the UTC time depicted on the UTC time display 305may be stable during the recording for the entire video frame for anylight integration time selected for the camera.

FIG. 3 is an illustration of one embodiment of a shutter timing testunit as depicted on a video monitor and shows the shutter timing testunit at the end of light integration. In order to measure the end oflight integration, the user may select the right edge or trailing edgeof the edge select switch 410, which may be a toggle switch on thecontrol unit 400. As a result, the UTC time depicted on the UTC timedisplay 305 may be synced to the time when the center timing LED 322 andcenter timing IR LED 332 stops illuminating. The user may also adjustthe settings on the control unit 400 as shown in FIG. 5. In particular,the user may adjust the offset time in single microsecond steps until:(1) the center timing LED 322 and center timing IR LED 332 illuminate;(2) the right timing LED 323 a adjacent to the center timing LED 322does not illuminate, and (3) right timing IR LED 333 a adjacent to thecenter timing IR LED 332 does not illuminate. At this time, both the endedge select LED indicator 350 and end edge select IR LED indicator 355may illuminate, thereby confirming that the trailing edge of a pulsesignal is selected for the measurement of the end of light integration.The UTC time shown in the UTC time display 305 may also be synchronizedto the trailing edge of that pulse signal at this time—that is, when:(1) the center timing LED 322 and center timing IR LED 332 illuminate;(2) the right timing LED 323 a adjacent to the center timing LED 322does not illuminate, and (3) right timing IR LED 333 a adjacent to thecenter timing IR LED 332 does not illuminate. Thus, as the right timingLED 323 a and the right timing IR LED 333 a illuminate, the UTC timedepicted on the UTC time display 305 may be stable during the recordingfor the entire video frame for any light integration time selected forthe camera.

FIG. 4 is an illustration of one embodiment of a control unit and showshow the settings of the control unit would be adjusted in order tomeasure the start of light integration. As discussed above, the controlunit 400 may be configured to send input timing signals to the shuttertiming test unit 300. In this manner, the user may adjust the timing andframe rate (i.e., frequency) of the illumination of the LEDs (i.e.,timing LEDs 320, BCD LEDs 325, timing IR LEDs 330, BCD IR LEDs 335) anddisplays (i.e., UTC time display 305, edge time display 310, pulse widthdisplay 315). Thus, by (1) adjusting the timing and frequency of theillumination of the LEDs and displays and (2) viewing the LEDs anddisplays through the monitor 125, the user may be able to measure thebeginning, end, and duration of light integration of the camera(s)focusing on the shutter timing test unit 300.

Importantly, FIG. 4 shows that the input timing signals may be adjustedby the user through the use of various toggle switches, buttons, andcontrol knobs. For example, as shown in FIG. 4, one embodiment of thecontrol unit 400 may comprise: timing range switches 405, 415, an edgeselect switch 410, a pulse width adjustment knob 420, an edge and framerate adjustment knob 425, and a frame rate push button 430.

The pulse width adjustment knob 420 may be a rotary control knob used toadjust the pulse width of one or more input timing signals in order toincrease or reduce the on-time lighting period of the LEDs and IR LEDs(i.e., number of microseconds that each timing LED and IR LED remainson). Specifically, the rotation of the pulse width adjustment knob 420may cause a pulse generator (not shown) to be adjusted for producing oneor more signals with a pulse width that preferably extends from the timewhen light integration begins until the time when light integrationends. Thus, by rotating and adjusting the pulse width adjustment knob420, the amount of time for each LED to remain lit may be shortened orlengthened, as desired.

In one implementation, multiple LEDs and IR LEDs may illuminate withinthe field of view of the visible camera 105 and infrared camera 110.Thus, when a user views the LEDs and IR LEDs of the shutter timing testunit 300 through the monitor 125, the user may measure the duration oflight integration time simply by adjusting the pulse width adjustmentknob 420 until the on-time lighting period of the LEDs and/or displaysis synchronized with the camera's sensor shutter time. This may occurwhen (1) the center timing LED 322 and center timing IR LED 332illuminate and (2) the LEDs adjacent to the center timing LED 322 andcenter timing IR LED 332 does not illuminate (e.g., left timing LED 321a, left timing IR LED 331 a, right timing LED 323 a, right timing IR LED333 a). Once the pulse width adjustment knob 420 is calibrated to havethe LEDs' illumination synchronized with the camera's sensor shuttertime, the user may read the pulse width display 315 to measure theduration of light integration time. As such, the pulse width adjustmentknob 420 may be used to measure the duration of light integration timeto the nearest microsecond.

Similarly, the edge and frame rate adjustment knob 425 may also be arotary control knob used to adjust the timing of a signal edge (i.e.,leading edge, trailing edge) for one or more input timing signals.Specifically, by rotating the edge and frame rate adjustment knob 425,the offset time of a leading edge or trailing edge of a pulse signal mayshift earlier or later, as desired. In this manner, a user may advanceor delay the timing of that signal edge relative to the camera'svertical synchronization signal 116 in order to measure the beginning orend of light integration time of a camera's shutter sensor.

In one implementation, multiple timing LEDs 320 and timing IR LEDs 330may light consecutively and in succession within the field of view ofthe visible camera 105 and/or infrared camera 110. Thus, when a userviews the illumination of the timing LEDs 320 and timing IR LEDs 330through the monitor 125, light integration time may be measured byaligning the illumination of the LEDs with the centermost LED (i.e., thecenter timing LED 322 and center timing IR LED 332). This is due to thefact that, as recited above, the UTC time shown in the UTC time display305 and the offset time shown in the edge time display 310 arepreferably synchronized with the center timing LED 322 and center timingIR LED 332. As a result, the beginning or end of light integration timemay be accurately measured by adjusting the edge and frame rateadjustment knob 425 until at least when the center timing LED 322 andcenter timing IR LED 332 illuminate. For instance, a user may measurethe beginning of light integration by: (1) aligning the leading edge ofthe pulse signal with the illumination of the center timing LED 322 andcenter timing IR LED 332 and (2) extinguishing the illumination of theleft timing LED 321 a and left timing IR LED 331 a. On the other hand,when measuring the end of light integration time, a user may: (1) alignthe trailing edge of the pulse signal with the illumination of thecenter timing LED 322 and center timing IR LED 332 and (2) extinguishingthe illumination of the right timing LED 323 a and right timing IR LED333 a.

Importantly, upon activating the frame rate push button 430, a user mayalso adjust the frequency of the illumination when adjusting the edgeand frame rate adjustment knob 425. This may allow a user to measure theframe rate of the camera under test. By way of example, in order tomeasure the frame rate of the camera, the user may actuate the framerate push button 430 and adjust the edge and frame rate adjustment knob425 until the user is able to read the numerical values on the UTC timedisplay 305, edge time display 310, or pulse width display 315.

In an embodiment, the shutter timing test unit 300 may be configured toenter into a default timing setting affecting the LEDs' and IR LEDs'on-time duration whenever the frame rate push button 430 is actuated.This may allow the LEDs' and IR LEDs' on-time illumination to cover theentire duration for a single vertical frame. In this manner, the on-timeduration of at least one LED and IR LED may be activated, and the usermay be able to quickly locate when light integration time occurs in thevideo frame. In particular, when viewing the LEDs or IR LEDs through themonitor 125, the user can simply view the LEDs and IR LEDs of theshutter timing test unit 300 and adjust the offset and on-timeillumination to move the first/last LED/IR LED towards the center LED/IRLED.

The edge select switch 410 may be a toggle switch used to select betweena leading edge or trailing edge of the pulse signal, and thus, may beused to select the start time or end time of light integration mode.

The timing range switches 405, 415 may be switches or control knobs usedto adjust the resolution or units of measure for the pulse widthadjustment knob 420 or edge and frame rate adjustment knob 425. Thetiming range switches 405, 415 may also be used to adjust the frequencyat which the LEDs, IR LEDs, and displays illuminate consecutively. Forinstance, as shown in FIG. 4, one embodiment of the timing range switch415 may have three adjustable positions (i.e., 100, 10, and 1microseconds). This may allow the user to adjust the resolution or unitsof measure of the pulse width adjustment knob 420 or edge and frame rateadjustment knob 425 to either 100, 10, or 1 microseconds.

More importantly, in order to measure the start of light integration, auser may adjust the settings on the control unit as shown in FIG. 4.Specifically, a user may configure the video timing test equipment 100to measure the beginning of light integration by selecting the left edgeor leading edge of the edge select switch 410. As a result, both thestart edge select LED indicator 340 and a start edge select IR LEDindicator 345 may illuminate, thereby confirming that the leading edgeof the pulse signal is selected for the measurement of the beginning oflight integration.

Additionally, in order to accurately measure the exact moment when lightintegration begins (i.e., noting the UTC time shown in the UTC timedisplay 305 and the offset time shown in the edge time display 310), theuser may also adjust the offset time in single microsecond incrementalsteps until the illumination of the left timing LED 321 a (adjacent tothe center timing LED 322) and left timing IR LED 331 a (adjacent to thecenter timing IR LED 332) extinguishes. The UTC time shown on the UTCtime display 305 may be synchronized with the timing at the beginning ofillumination of the center timing LED 322 and center timing IR LED 332,thereby indicating the beginning of light integration time. In apreferred embodiment, the UTC time shown in the UTC time display 305 maybe stable throughout the recording for the entire video frame for anylight integration time selected for the camera.

FIG. 5 is an illustration of one embodiment of a control unit and showshow the settings of the control unit would be adjusted in order tomeasure the end of light integration. As shown in FIG. 5, one embodimentof the control unit 400 may comprise: timing range toggle switches 405,415, an edge select toggle switch 410, a pulse width adjustment knob420, an edge and frame rate adjustment knob 425, and a frame rate pushbutton 430. In order to measure the end of light integration, a user mayadjust the settings on the control unit 400, as shown in FIG. 5.Specifically, a user may begin configuring the video timing testequipment 100 for measuring the end of light integration by selectingthe right edge or trailing edge of the edge select switch 410. As aresult, the end edge select LED indicator 350 and end edge select IR LEDindicator 355 may illuminate, thereby confirming that the trailing edgeof the pulse signal is selected for the measurement of the end of lightintegration.

Additionally, in order to accurately measure the exact moment when lightintegration ends (i.e., noting the UTC time shown in the UTC timedisplay 305 and the offset time shown in the edge time display 310), theuser may also adjust the offset time in single microsecond incrementalsteps until the illumination of the right timing LED 323 a (adjacent tothe center timing LED 322) and right timing IR LED 333 a (adjacent tothe center timing IR LED 332) extinguishes. As discussed above, the UTCtime shown on the UTC time display 305 may be synchronized with thetiming at the end of illumination of the center timing LED 322 andcenter timing IR LED 332, thereby indicating the end of lightintegration time. In a preferred embodiment, the UTC time shown in theUTC time display 305 may be stable throughout the recording for theentire video frame for any light integration time selected for thecamera.

FIG. 6 is a block diagram of the video timing test equipment accordingto various embodiments of the present disclosure. As shown in FIG. 6,one embodiment of the video timing test equipment 100 may comprise: ashutter timing test source 300 and control unit 400. FIG. 6 also showsthat the shutter timing test source 300 may also comprise: a UTC timinglogic module 605, user input and display module 610, and an LED and UTCoutput module 615.

The UTC timing logic module 605 may be one or more components or devicesconfigured to generate a current UTC time signal 616 representing thecurrent time in UTC format. In one implementation, the UTC timing logicmodule 605 may comprise: a set UTC time logic 606, an adjustmentregister 607, and a UTC time counter 608. The set UTC time logic 606 maybe an interface logic configured to receive GPS signals (i.e., a onepulse per second (1PPS) GPS signal 602 (e.g., L1 signal) and GPS UTCtime message 603) from a typical GPS receiver 200, shown in FIG. 1. Theset UTC time logic 606 may also be configured determine the UTC time andprovide the following outputs: (1) the 1PPS GPS signal 602 to the UTCtime counter 608 and (2) the GPS UTC time message 603 to the adjustmentregister 607. In this manner, the adjustment register 607 may latch theUTC time message 603 and output the adjusted UTC set time signal 604,which may be a delay in UTC time to the nearest microsecond due topropagation delay. The adjusted UTC set time signal 604 may thenincrement the UTC time counter 608 to generate the current UTC timesignal 616, which may be synchronized with the 1PPS signal 602. Invarious embodiments, a clock signal 609 may also be aligned to the 1PPSsignal 602 for correction and improvement towards timing accuracy.

FIG. 6 also shows that the shutter timing test source 300 may alsocomprise a user input and display module 610. The user input and displaymodule 610 may be configured to receive input timing signals from thecontrol unit 400 and may display some of the user inputs via the edgetime display 310 and pulse width display 315. Importantly, the userinput and display module 610 may also be configured to generate a pulsewidth signal 614 and a first timing LED start time signal 613 based onthe input timing signals. As recited above, the pulse width signal 614may control the length or duration of the on-time lighting orillumination of each timing LED 320 and timing IR LED 330. The firsttiming LED start time signal 613 may transmit LED start time informationto the LED and UTC output module 615 for controlling the illumination ofthe timing LEDs 320 and timing IR LEDs 330.

By way of example, one embodiment of the user input and display module610 may comprise a user input display logic 611 and timing logic 612.The user input display logic 611 may receive from the control unit 400various input timing signals configurable by the user. Examples of suchinput timing signals may include, without limitation, anincremented/decremented pulse width signal 651, incremented/decrementededge time signal 652, start/stop select signal 653, andincrement/decrement frame rate signal 654. A summary of the functionsfor these input timing signals are described below in Table 1.

TABLE 1 Incremented/Decremented Controls length of pulse width of asignal Pulse Width Signal Incremented/Decremented Controls offset timeof the leading Edge Time Signal edge/trailing edge of a pulse signalStart/Stop Select Signal Selects between leading edge/trailing edge of apulse signal Increment/Decrement Frame Controls frequency ofillumination for the Rate Signal LEDs and displays

Upon receiving these input timing signals, the user input display logic611 may show these user input values on the edge time display 310 andpulse width display 315. Specifically, the edge time display 310 maydepict the edge time or offset time at which the illumination of thetiming LEDs 320 and timing IR LEDs 330 begins or ends. In particular,the edge time display 310 may depict the offset time at which the timingLEDs 320 and timing IR LEDs 330 begin to illuminate, which is preferablyat the start of integration time (i.e., the leading edge).Alternatively, the edge time display 310 may also depict the offset timeat which the timing LEDs 320 and timing IR LEDs 330 stop illuminating,which is preferably at the end of integration time (i.e., trailingedge). The pulse width display 315 may show a pulse width time value,indicating the duration at which each of the timing LEDs 320 and timingIR LEDs 3305 illuminate.

In one embodiment, the edge time display 310 may depict the edge time oroffset time in microseconds. Similarly, the pulse width display 315 mayalso depict the pulse width time in microseconds.

The user input display logic 611 may also output various timing signalsreadable by the timing logic 612, including: an edge selected signal661, edge time signal 662, pulse width signal 663, and frame rate signal664. The functionality of these timing signals may be similar to theinput timing signals received from the control unit 400 and aredescribed below in Table 2.

TABLE 2 Pulse Width Signal Includes information regarding length of thepulse width of a signal Edge Time Signal Includes offset timeinformation for the leading edge or trailing edge of a pulse signal EdgeSelected Signal Includes information regarding whether leading edge ortrailing edge of a pulse signal is selected Frame Rate Signal Includesinformation regarding frequency of the illumination for the LEDs anddisplays

Using the above timing signals shown in Table 2 and the current UTC timesignal 616 generated by the UTC timing module 605, the timing logic 612of the user input and display module 610 may generate: (1) a firsttiming LED start time signal 613, (2) a pulse width signal 614, and (3)a center timing LED UTC time matching signal 633. As recited above, thepulse width signal 614 may transmit information regarding the durationof the on-time lighting of the LEDs, IR LEDs, and displays (i.e.,duration of light integration). The first timing LED start time signal613 may include information regarding the illumination of the first LEDfrom a series of multiple timing LEDs 320 and timing IR LEDs 330. Thisfirst timing LED start time signal 613 can also be used to helpdetermine the on-time lighting periods for the remaining timing LEDs 320and timing IR LEDs 330. The center timing LED UTC time matching signal633 may include UTC timing information for the start/end of lightintegration of the center timing LED 322 and the center timing IR LED332. The center timing LED UTC time matching signal 633 may also begenerated based on the current UTC time signal 616 derived from the UTCtiming logic module 605 in order to display the start or end of lightintegration in UTC time.

FIG. 6 also shows that the shutter timing test source 300 may alsocomprise an LED and UTC output module 615. The LED and UTC output module615 may be configured to illuminate the timing LEDs 320, BCD LEDs 325,timing IR LEDs 330, and BCD IR LEDs 335 for purposes of determining thebeginning or end of light integration of a camera under test. The LEDand UTC output module 615 may also regulate the illumination of theseLEDs and IR LEDs at various time intervals, based on various inputsignals such as the clock signal 609, current UTC time signal 616, firsttiming LED start time signal 613, and pulse width signal 614.

Importantly, the LED and UTC output module 615 may also be configured toshow UTC time in the UTC time display 305. In a preferred embodiment,the displayed UTC time on the UTC time display 305 may be synchronizedwith the illumination of the center timing LED 322 and the center timingIR LED 332. In this manner, the UTC time displayed on the UTC timedisplay 305 represents the offset time for the leading edge or trailingedge of the center timing LED output signal, which may control theillumination of the center timing LED 322 and the center timing IR LED332.

By way of example, one embodiment of the LED and UTC output module 615may comprise a comparator 617, an output controller 618, and a UTC timedisplay 305. The comparator 617 may receive both the current UTC timesignal 616 and the first timing LED start time signal 613 and maygenerate, based on these two signals, a start output signal 619 for theoutput controller 618. The start output signal 619 may transmit timinginformation as to when the timing LEDs 320 and timing IR LEDs 330 beginor stop illuminating. In particular, when the leading edge of the edgeselect toggle switch 410 of the control unit 400 is selected, the startoutput signal 619 may transmit UTC timing information as to the timewhen the timing LEDs 320 and timing IR LEDs 330 begin illuminating(i.e., beginning of light integration, leading edge of pulse signal).Alternatively, when the trailing edge of the edge select toggle switch410 is selected, the start output signal 619 may transmit UTC timinginformation as to the time when the timing LEDs 320 and timing IR LEDs330 stop illuminating (i.e., end of light integration, trailing edge ofpulse signal).

In addition to the start output signal 619, the output controller 618may also receive the pulse width signal 614 from the timing logic 612.Given the pulse width signal 614 and the start output signal 619, theoutput controller 618 may be able to determine the offset times or starttimes for illuminating one or more timing LEDs 320 and timing IR LEDs330. As a result, the output controller 618 may also generate multipletiming LED output signals 631 to regulate the illumination of one ormore timing LEDs 320 and timing IR LEDs 330. In this manner, each timingLED output signal 631 may comprise a pulse waveform that followsconsecutively and sequentially from one another (as shown in FIG. 7),such that the leading edge of each timing LED output signal may bealigned with the trailing edge of the preceding timing LED outputsignal. To help increase correction and timing accuracy for the timingLED output signals 631, a clock signal 609 may also be used inconjunction with the output controller 618.

FIG. 6 also shows that both the timing logic 612 and the outputcontroller 618 are in communication with the UTC time display 305. Here,the timing logic 612 may transmit to the UTC time display 305 a centerLED UTC time matching signal 633, which may carry UTC time informationsynchronized with the leading edge or trailing edge of the center timingLED output signal for the center timing LED 322 and the center timing IRLED 332. Additionally, the output controller 618 may transmit a centerLED on signal 632 to activate the UTC time display 305 whenever thecenter timing LED 322 and the center timing IR LED 332 illuminate. Inthis manner, using the timing logic 612 and output controller 618, theUTC time display 305 may depict the UTC time when the center timing LED322 and the center timing IR LED 332 begin to illuminate (i.e., start oflight integration) or stops illuminating (i.e., end of lightintegration).

FIG. 6 also shows that the output controller 618 may be in communicationwith the BCD LEDs 325 and BCD IR LEDs 335. As recited above, the BCDLEDs 325 and BCD IR LEDs 335 may be configured to illuminate the UTCtime value shown in the UTC time display 305 in BCD format. In otherwords, the BCD LEDs 325 and BCD IR LEDs 335 may display in BCD formatthe UTC time when the center timing LED 322 and the center timing IR LED332 illuminate. This will allow the user to verify the time stampinserted in the video data by matching the UTC time when lightintegration occurs. In one embodiment, the BCD LEDs 325 and BCD IR LEDs335 may be grouped into four LEDs per group as 4-bit LEDs, as shown inFIGS. 2 and 3.

In various embodiments, the UTC time display 305, edge time display 310,and/or pulse width display 315 may comprise one or more seven segmentdisplays. For instance, in one embodiment shown in FIGS. 2 and 3, theUTC time display 305 may comprise seven segment digital displays—i.e., asingle seven segment digital display for displaying a second unit oftime (i.e., a first seven segment digital display), three seven segmentdigital displays capable of displaying a millisecond unit of time (i.e.,a second, third, and fourth seven segment digital display), and threeadditional seven segment digital displays capable of depicting amicrosecond unit of time (i.e., a fifth, sixth, and seventh sevensegment digital displays).

FIGS. 7A and 7B are illustrations of some embodiments of the timingLEDs, timing IR LEDs, and timing LED output signals and show the timingrelationship of these timing LEDs, timing IR LEDs, and timing LED outputsignals. Specifically, FIG. 7A shows the timing LEDs 320, including:left timing LEDs 321 a, 321 b, center timing LED 322, and right timingLEDs 323 a, 323 b. Left timing LED 321 a and right timing LED 323 a areadjacent to center timing LED 322.

FIG. 7A also shows the timing IR LEDs 330, including: the left timing IRLEDs 331 a, 331 b, center timing IR LED 332, and right timing IR LEDs333 a, 333 b. Left timing IR LED 331 a and right timing IR LED 333 a areadjacent to center timing LED 332.

Finally, FIG. 7B shows the timing LED output signals 701, 702, 703, 704,705.

FIGS. 7A and 7B show one embodiment of the timing relationship for thetiming LEDs 320, timing IR LEDs 330, and timing LED output signals 701,702, 703, 704, 705. First of all, when a user adjusts the settings ofthe control unit 400 to match the light integration time of a camerawith the illumination of the center timing LED 322 and center timing IRLED 332, timing LED output signal 701 may correspond with theillumination of first left timing LED 321 b and first left timing IRLEDs 331 b. Additionally, timing LED output signal 702 may correspondwith the illumination of the second left timing LED 321 a and secondleft timing IR LED 331 a while center timing LED output signal 703 maycorrespond with the illumination of center timing LED 322 and centertiming IR LED 332. Timing LED output signal 704 may correspond with theillumination of first right timing LED 323 a and first right timing IRLED 333 a, and timing LED output signal 705 may correspond with theillumination of second right timing LED 323 b and second right timing IRLED 333 b. Although FIG. 7B shows five timing LED output signals,additional timing LED output signals may be used without deviating fromthe scope of disclosure.

Importantly, FIG. 7B shows that the offset times of the pulse waveformsfor each timing LED output signals 701, 702, 703, 704, 705 may occursequentially and successively, such that the timing LEDs 320 and timingIR LEDs 330 illuminate in a consecutive manner. In particular, theleading and trailing ends of the pulse waveforms for each timing LEDoutput signals 701, 702, 703, 704, 705 may align with one anothersuccessively. In this manner, the timing LED output signals 701, 702,703, 704, 705 may illuminate the timing LEDs 320 and timing IR LEDs 330in sequential order. By way of example, as shown in FIGS. 7A and 7B,timing LED output signal 701 may include a pulse width waveform thatbegins illuminating the first left timing LED 321 b and first lefttiming IR LEDs 331 b. At the trailing end of the pulse width waveform oftiming LED output signal 701, the pulse width waveform of timing LEDoutput signal 702 may begin to illuminate the second left timing LED 321a and second left timing IR LED 331 a. At the trailing end of the pulsewidth waveform of timing LED output signal 702, center timing LED outputsignal 703 may then begin illuminating the center timing LED 322 andcenter timing IR LED 332. Timing LED output signal 704 may thenilluminate the first right timing LED 323 a and first right timing IRLED 333 a thereafter. Finally, timing LED output signal 705 mayilluminate the second right timing LED 323 b and second right timing IRLED 333 b.

In one implementation, adjusting the offset time to illuminate thecenter timing LED 322 and center timing IR LED 332 may be configured bythe user to indicate either the start of integration time or the end ofintegration time. Here, as the trailing edge 709 b of timing LED outputsignal 702 completes illuminating first left timing LED 321 b and firstleft timing IR LEDs 331 b, the leading edge 710 a of center timing LEDoutput signal 703 may begin to illuminate the center timing LED 322 andcenter timing IR LED 332. At this time, light integration begins, andthe user may note the UTC time on the UTC time display 305 if theleading edge is selected. Conversely, as the trailing edge 710 b ofcenter timing LED output signal 703 completes the illumination of thecenter timing LED 322 and center timing IR LED 332, the leading edge 711a of timing LED output signal 704 may begin to illuminate the firstright timing LED 323 a and first right timing IR LED 333 a. At thistime, light integration ends and the user may note the UTC time on theUTC time display 305 if the trailing edge is selected. As such, the UTCtime on the UTC time display 305 may indicate when both the centertiming LED 322 and center timing IR LED 332 began illuminating at thestart of integration time and may display the UTC time when the centertiming LED 322 and center timing IR LED 332 stops illumination at theend of integration time. The pulse width display 315 may indicate thelength of time each of the timing LEDs 320 and timing IR LEDs 330 beginilluminating.

While the foregoing written description enables one of ordinary skill tomake and use what is considered presently to be the best mode thereof,those of ordinary skill will understand and appreciate the existence ofvariations, combinations, and equivalents of the specific embodiment,method, and examples herein. The components, steps, features, objects,benefits, and advantages that have been discussed are merelyillustrative, and none of them, nor the discussions relating to them,are intended to limit the scope of protection in any way. Numerous otherembodiments are also contemplated, including embodiments that havefewer, additional, and/or different components, steps features, objects,benefits, and advantages. The components and steps may also be arrangedand ordered differently.

The foregoing description of the preferred embodiment has been presentedfor the purposes of illustration and description. While multipleembodiments are disclosed, still other embodiments will become apparentto those skilled in the art from the above detailed description. As willbe realized, the scope of protection is capable of modifications invarious obvious aspects, all without departing from the spirit and scopeof the present disclosure. Accordingly, the detailed description is tobe regarded as illustrative in nature and not restrictive. Also,although not explicitly recited, one or more embodiments may bepracticed in combination or conjunction with one another. Furthermore,the reference or non-reference to a particular embodiment shall not beinterpreted to limit the scope of protection. It is intended that thescope of protection not be limited by this detailed description, but bythe claims and the equivalents to the claims that are appended hereto.

Except as stated immediately above, nothing which has been stated orillustrated is intended or should be interpreted to cause a dedicationof any component, step, feature, object, benefit, advantage, orequivalent to the public, regardless of whether it is or is not recitedin the claims. The scope of protection is limited solely by the claimsthat now follow, and that scope is intended to be broad as is reasonablyconsistent with the language that is used in the claims. The scope ofprotection is also intended to be broad to encompass all structural andfunctional equivalents.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:
 1. A video timing test equipment formeasuring light integration time of a camera under test, comprising: acontrol unit capable of generating a plurality of input timing signalsadjustable by a user; and a shutter timing test unit operatively coupledto said control unit, said shutter timing test unit comprising: aplurality of timing light emitting diodes (LEDs), including: at leastone left timing LED, a center timing LED, and at least one right timingLED; and an output controller capable of regulating an illumination ofsaid plurality of timing LEDs by generating a plurality of timing LEDoutput signals, each having an offset time occurring sequentially andcorresponding to an associated one of said plurality of timing LEDs;wherein said plurality of timing LED output signals are adjusted by saiduser based on said plurality of input timing signals; wherein saidplurality of timing LED output signals include a center timing LEDoutput signal associated with said illumination of said center timingLED; and wherein said output controller is configured to: i) illuminatesaid center timing LED based on said offset time of said center timingLED output signal; ii) illuminate said at least one left timing LEDbefore said illumination of said center timing LED; and iii) illuminatesaid at least one right timing LED after said illumination of saidcenter timing LED.
 2. The video timing test equipment according to claim1, wherein said shutter timing test unit further comprises; acoordinated universal time (UTC) time display in communication with saidoutput controller; a UTC timing module capable of generating a currentUTC time signal; and a timing logic capable of generating a centertiming LED UTC time matching signal based on said current UTC timesignal and said plurality of input timing signals; wherein said outputcontroller is capable of displaying on said UTC time display a UTC timebased on said center timing LED UTC time matching signal, said UTC timecorresponding to a UTC start time or a UTC end time of said lightintegration.
 3. The video timing test equipment, according to claim 2,wherein said shutter timing test unit further comprises: a plurality ofbinary coded decimal (BCD) LEDs in communication with said outputcontroller; and wherein said output controller is capable of displayingsaid UTC time in BCD format with said plurality of BCD LEDs.
 4. Thevideo timing test equipment, according to claim 3, wherein said shuttertiming test unit further comprises: a plurality of BCD infrared lightemitting diodes (IR LEDs) in communication with said output controller;wherein said output controller is capable of displaying said UTC time inBCD format with said plurality of BCD IR LEDs.
 5. The video timing testequipment according to claim 1, wherein said shutter timing test unitfurther comprises: a user input display logic; and an edge time displayin communication with said user input display logic; wherein said userinput display logic is capable of displaying said offset time of saidcenter timing LED on said edge time display based on said plurality ofinput timing signals.
 6. The video timing test equipment according toclaim 5, wherein said shutter timing test unit further comprises: apulse width display in communication with said user input display logic;wherein said user input display logic is capable of displaying a pulsewidth time on said pulse width display based on said plurality of inputtiming signals.
 7. The video timing test equipment, according to claim1, wherein said shutter timing test unit further comprises: a pluralityof timing IR LEDs, including at least one left timing IR LED, a centertiming IR LED, and at least one right timing IR LED; wherein said outputcontroller is capable of regulating an illumination of said plurality oftiming IR LEDs based on said plurality of timing LED output signals,such that said output controller is configured to: i) illuminate saidcenter timing IR LED based on said offset time of said center timing LEDoutput signal; ii) illuminate said at least one left timing IR LEDbefore said illumination of said center timing IR LED; and iii)illuminate said at least one right timing IR LED after said illuminationof said center timing IR LED.
 8. The video timing test equipment ofclaim 1, wherein said control unit comprises a toggle switch movablebetween a start position and an end position, said start position beingassociated with a leading edge of said center timing LED output signaland said end position being associated with a trailing edge of saidcenter timing LED output signal, such that said start positioncorresponds to a start of light integration and said end positioncorresponds to an end of said light integration.
 9. A method formeasuring light integration time of a camera under test with a videotiming test equipment, comprising: providing a video timing testequipment, comprising: a control unit and a shutter timing test unit;wherein said control unit is capable of generating a plurality of inputtiming signals adjustable by a user and comprises: (1) a toggle switchselectable between a start of light integration and an end of lightintegration and (2) at least one rotary control knob adjustable for anoffset time of said start and said end of light integration; whereinsaid shutter timing test unit is operatively coupled to said controlunit and comprises: a plurality of timing LEDs, including: at least oneleft timing LED, a center timing LED, and at least one right timing LED;and an output controller capable of regulating an illumination of saidplurality of timing LEDs by generating a plurality of timing LED outputsignals, each having an offset time increasing successively andcorresponding to an associated one of said plurality of timing LEDs,said plurality of timing LED output signals being adjusted based on saidplurality of input timing signals; positioning said shutter timing testunit in view of a camera under test, such that, a monitor in videocommunication with said camera under test displays a video image of saidtiming LEDs of said shutter timing test unit; adjusting said toggleswitch of said control unit to select said start of light integration;and while viewing said timing LEDs on said monitor, adjusting said atleast one control knob of said control unit until said at least one lefttiming LED stops illuminating and said center timing LED illuminates inorder to measure said start of said light integration.
 10. The methodfor measuring light integration time of claim 9, wherein said pluralityof timing LED output signals includes a center timing LED output signalassociated with said illumination of said center timing LED; and whereinsaid output controller is configured to: i) illuminate said centertiming LED based on said offset time of said center timing LED outputsignal; ii) illuminate said at least one left timing LED before saidillumination of said center timing LED; and iii) illuminate said atleast one right timing LED after said illumination of said center timingLED.
 11. The method for measuring light integration time of claim 9,further comprising the steps: adjusting said toggle switch of saidcontrol unit to select said end of said light integration; and whileviewing said timing LEDs on said monitor, adjusting said at least onecontrol knob of said control unit until said at least said center timingLED illuminates and said at least one right timing LED stopsilluminating in order to determine said end of light integration. 12.The method for measuring light integration time of claim 9, wherein saidshutter timing test unit further comprises a UTC time display; whereinsaid UTC time display depicts a UTC start time when selecting said startof said light integration with said control unit; and wherein saidmethod further comprising the steps: adjusting said toggle switch ofsaid control unit to select said start of light integration; andverifying that a UTC time overlay displayed on said monitor andgenerated by said camera under test is substantially identical to saidUTC start time depicted on said UTC time display of said shutter timingtest unit.
 13. The method for measuring light integration time of claim12, wherein said UTC time display depicts a UTC end time when selectingsaid end of light integration with said control unit; and wherein saidmethod further comprising the steps: adjusting said toggle switch ofsaid control unit to select said end of light integration; and verifyingthat a UTC time overlay displayed on said monitor and generated by saidcamera under test is substantially identical to said UTC end timedepicted on said UTC time display of said shutter timing test unit. 14.A method for measuring light integration time of an infrared (IR) cameraunder test with a video timing test equipment, comprising: providing avideo timing test equipment comprising: a control unit and a shuttertiming test unit; wherein said control unit is capable of generating aplurality of input timing signals adjustable by a user and comprises:(1) a toggle switch selectable between a start of light integration andan end of light integration and (2) at least one rotary control knobadjustable for an offset time of said start and said end of lightintegration; wherein said shutter timing test unit is operativelycoupled to said control unit and comprises: a plurality of timing IRLEDs, including: at least one left timing IR LED, a center timing IRLED, and at least one right timing IR LED; and an output controllercapable of regulating an illumination of said plurality of timing IRLEDs by generating a plurality of timing LEE) output signals, eachhaving an offset time increasing successively and corresponding to anassociated one of said plurality of timing IR LEDs, said plurality oftiming LED output signals being adjusted based on said plurality ofinput timing signals; positioning said shutter timing test unit in viewof an IR camera under test, such that, a monitor in video communicationwith said IR camera under test displays a video image of said timing IRLEDs of said shutter timing test unit; adjusting said toggle switch ofsaid control unit to select said start of light integration; and whileviewing said timing IR LEDs on said monitor, adjusting said at least onecontrol knob of said control unit until said at least one left timing IRLED stops illuminating and said center timing IR LED illuminates inorder to measure said start of said light integration.
 15. The methodfor measuring light integration time of claim 14, wherein said pluralityof timing LED output signals includes a center timing LED output signalassociated with said illumination of said center timing IR LED; andwherein said output controller is configured to: i) illuminate saidcenter timing IR LED based on said offset time of said center timing LEDoutput signal; ii) illuminate said at least one left timing IR LEDbefore said illumination of said center timing LED; and iii) illuminatesaid at least one right timing IR LED after said illumination of saidcenter timing LED.
 16. The method for measuring light integration timeof claim 14, further comprising the steps: adjusting said toggle switchof said control unit to select said end of said light integration; andwhile viewing said timing IR LEDs on said monitor, adjusting said atleast one control knob of said control unit until said at least saidcenter timing IR LED illuminates and said at least one right timing IRLED stops illuminating in order to determine said end of lightintegration.
 17. The method for measuring light integration time ofclaim 14, wherein said shutter timing test unit further comprises a UTCtime display; wherein said UTC time display depicts a UTC start timewhen selecting said start of said light integration with said controlunit; and wherein said method further comprising the steps: adjustingsaid toggle switch of said control unit to select said start of lightintegration; and verifying that a UTC time overlay displayed on saidmonitor and generated by said IR camera under test is substantiallyidentical to said UTC start time depicted on said UTC time display ofsaid shutter timing test unit.
 18. The method for measuring lightintegration time of claim 17, wherein said UTC time display depicts aUTC end time when selecting said end of light integration with saidcontrol unit; and wherein said method further comprising the steps:adjusting said toggle switch of said control unit to select said end oflight integration; and verifying that a UTC time overlay displayed onsaid monitor and generated by said IR camera under test is substantiallyidentical to said UTC end time depicted on said UTC time display of saidshutter timing test unit.